Piston rod air cleaning device

ABSTRACT

A piston rod air cleaning device in which the exhaust air of a pneumatic motor is fed to a chamber surrounding a piston rod at the end of the cylinder throughwhich the piston rod reciprocates. The air flows axially of the piston rod away from the cylinder to carry all dirt and foreign material away from the cylinder. In hydraulic actuated cylinders a similar chamber is provided and fed with air from a separate air supply.

Unite States atent n 1 Marrara [4 1 Apr. 24,1973

1 1 PISTON ROD AIR CLEANING DEVICE [76] Inventor: Robert S. Marrara, Box 172,

- Arthurdale, W. Va. 26520 22 Filed: Jan. 15,1971

21 Appl. No.: 106,860

[52] US. Cl ..92/87, 15/300 R, 55/282 [51] Int. Cl ..FOlb 31/00 [58] Field of Search ..277/71, 72;

15/306 A, 306 B, 306 R, 300 R; 134/122; 91/466, 471; 92/87; 415/112 [56] References Cited UNITED STATES PATENTS 2,878,990 3/1959 Zurcher ..184/24 245,774 8/1881 Brazelle i ..91/466 1,136,928 4/1915 Bodinson ..415/112 1,232,797 7/1917 Hedendahl ..91/466 1,376,043 4/1921 Sherwood ..415/1 12 1,813,016 7/1931 Bentley i ..277/72 2,542,237 2/1951 Dewey 1 34/122 3,045,650 7/1962 Ambrosini... ..277/72 3,270,364 9/1966 Steele ..15/306 A Primary Examiner-Bernard Nozick Attorney-Victor J. Evans & Co.

[ 5 7 ABSTRACT 6 Claims, 7 Drawing Figures I III/I II III III PISTON ROD AIR CLEANING DEVICE BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to air purge cleaners for piston rods to prevent the piston rod from carrying dirt into the cylinder of pneumatic or hydraulically actuated cylinders.

SUMMARY OF THE INVENTION In the present invention the exhaust air from a conventional pneumatic cylinder or air motor is fed to a chamber surrounding the piston rod at the end of the cylinder through-which the piston rod reciprocates with the air being allowed to escape from the chamber axially along the surface of the piston rod to sweep all dirt and foreign material away from the cylinder to thus avoid contamination of the interior of the cylinder.

The primary object of the invention is to provide an air purge cleaning device which will completely eliminate all contamination of the type normally carried into the cylinder by the piston rod.

Other objects and advantages will become apparent in the following specification when considered in the light of the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of the invention;

FIG. 2 is a transverse cross-section taken along the line 2-2 of FIG. 1, looking in the direction of the arrows;

FIG. 3 is a transverse sectional view taken along the line 33 of FIG. 1, looking in the direction of the arrows;

FIG. 4 is a longitudinal sectional view of a modified form of the invention shown partially broken away and in section for convenience of illustration;

FIG. 5 is a transverse sectional view taken along the line 55 of FIG. 4, looking in the direction of the arrows;

FIG. 6 is a longitudinal sectional view of another modified form of the invention shown partially broken away for convenience of illustration; and

FIG. 7 is a transverse sectional view taken along the line 7-7 of FIG. 6, looking in the direction of the arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail wherein like reference characters indicate like parts throughout the several figures the reference numeral 10 indicates generally an air purge cleaning device constructed in accordance with the invention.

The air purge cleaning device 10 is adapted for use with a pneumatically actuated power cylinder indicated generally at II. The power cylinder 11 includes an elongate hollow cylinder 12 closed at its opposite ends by heads 13, 14. A valve 15 conventionally controls the flow of air from an air inlet conduit 16 to an air conduit 17 which extends to and through the head 13 and an air conduit 18 which extends to and through the head 14. The valve 15 also controls the flow of exhaust air to an exhaust air conduit 19.

A piston 20 is mounted for reciprocation in the cylinder 12 on the inner end of a piston rod 21. The piston rod 21 extends through the head 14 and a seal 22 in the head 14 prevents the escape of media from the cylinder 12 while permitting the piston rod 21 to reciprocate through the head 14.

A chamber 23 encompasses the piston rod 21 and is secured to the head 14 by a plurality of cap screws 24. The chamber 23 has a bore 25 extending therethrough with a diameter, which can be adjusted to suit required maximum piston speed, but greater than the outer diameter of the piston rod 21.

The exhaust air conduit 19 extending from the valve 15 is connected at its opposite end to the chamber 23 so that exhaust air flowing from the cylinder 12 from either side of the piston 20 is directed through the exhaust air conduit 19 and flows into the chamber 23. Exhaust air in the chamber 23 flows outwardly therefrom around the piston rod 21 through the bore 25. The flow of air outwardly through the bore 25 scrubs the outer surface of the piston rod 21 as it moves through the head 14 forcing all dirt and contaminating material away from the head 14 so that it is not carried through the head 14 into the cylinder 12.

In some instances the power cylinder 11 will be conventionally actuated by hydraulic means in which case the exhaust air conduit 19 will extend to a source of air under pressure which is permitted to flow into the chamber 23 and out through the bore 25 at all times that the power cylinder 11 is in operation.

In FIG. 4 a modified form of the invention illustrated wherein the cylinder 11 is provided with a head 14' having a seal 22' for engaging the outer surface of the piston rod 21. the head 14' has an integral chamber 23 formed therein surrounding the piston rod 21 and having a bore 25 which opens around the piston rod 21 to permit the flow of air to scrub the surface of the piston rod 21. The exhaust air conduit 19 is connected to the head 14' so as to communicate with the chamber 23' so that exhaust air from the cylinder 11 can be continuously fed into the chamber 23' and out through the bore 25' along the surface of the piston rod 21. The operation of the modified form of the invention illustrated in FIGS. 4 and 5 is identical to the preferred form of the invention illustrated in FIG. 1.

In FIGS. 6 and 7 another modified form of the invention is illustrated wherein the cylinder 11 is provided with a head 14" throughwhich the piston rod 21 extends sealed by a seal 22". The head 14" has a chamber 23" formed therein surrounding the piston rod 21 outwardly of the seal 22". A cover 26 is detachably secured to the head 14" with the piston rod 21 extending through an axial bore 25" formed in the cover 26. The bore 25" has a diameter somewhat greater then the outer diameter of the piston rod 21 to permit the flow of air out of the chamber 23" along the face of the piston rod 21. The air conduit 18 is connected to the head 14' to communicate with the interior of the cylinder 11 and the air conduit 19 is connected to the head 14 to communicate with the chamber 23".

The use and operation of the modification illustrated in FIGS. 6 and 7 is identical to that of the preferred form of the invention illustrated in FIGS. 1 through 3.

It should be understood that the present invention is adapted for use with any device in which a piston rod moves into and out of a cylinder through a head to prevent the piston rod from carrying contaminated materials into the cylinder through the head.

Having thus described the preferred embodiment of the invention it should be understood that numerous structural modifications and adaptations may be resorted to without departing from the spirit of the invention.

What is claimed is:

1. A piston rod air cleaning device comprising a power cylinder, a head on each end of said cylinder, a piston in said cylinder, a piston rod connected to said piston and extending through the head in sealed relationship therewith on one end of the cylinder and means for reciprocating the piston Within the cylinder, a chamber on the one head with the piston rod extending therethrough, a bore formed in said chamber defining an exhaust air outlet through which said piston rod extends with said bore having a diameter greater than the outer diameter of said piston rod so as to be spaced from said piston rod, and means for supplying air under pressure to said chamber to clean the piston rod and to provide a flow of air outwardly through said bore.

2. A device as claimed in claim 1 wherein said chamber is detachably secured to said head in surrounding relation to said piston rod.

3. A device as claimed in claim 1 wherein said chamber is formed in said head surrounding said piston rod.

4. A device as claimed in claim 1 wherein said chamber is formed in said head surrounding said piston rod and a cover for said chamber is secured to said head surrounding said piston rod with said cover having a bore throughwhich said piston rod extends with said bore having a diameter greater then the external diameter of said piston rod.

5. A device as claimed in claim 1 wherein the means for supplying air to said chamber extends from a control valve for said cylinder and supplies air from said cylinder to said chamber.

6. A device as claimed in claim 1 wherein the means for supplying air to said chamber extends from a source of air under pressure. 

1. A piston rod air cleaning device comprising a power cylinder, a head on each end of said cylinder, a piston in said cylinder, a piston rod connected to said piston and extending through the head in sealeD relationship therewith on one end of the cylinder and means for reciprocating the piston within the cylinder, a chamber on the one head with the piston rod extending therethrough, a bore formed in said chamber defining an exhaust air outlet through which said piston rod extends with said bore having a diameter greater than the outer diameter of said piston rod so as to be spaced from said piston rod, and means for supplying air under pressure to said chamber to clean the piston rod and to provide a flow of air outwardly through said bore.
 2. A device as claimed in claim 1 wherein said chamber is detachably secured to said head in surrounding relation to said piston rod.
 3. A device as claimed in claim 1 wherein said chamber is formed in said head surrounding said piston rod.
 4. A device as claimed in claim 1 wherein said chamber is formed in said head surrounding said piston rod and a cover for said chamber is secured to said head surrounding said piston rod with said cover having a bore throughwhich said piston rod extends with said bore having a diameter greater then the external diameter of said piston rod.
 5. A device as claimed in claim 1 wherein the means for supplying air to said chamber extends from a control valve for said cylinder and supplies air from said cylinder to said chamber.
 6. A device as claimed in claim 1 wherein the means for supplying air to said chamber extends from a source of air under pressure. 